bug#47951: 28.0.50; Recent seccomp changes break compilation in Docker

Hi,

Since the recent changes introduced by Philipp Stephani on seccomp (around
commit be8328acf9aa464f848e682e63e417a18529af9e), compiling Emacs from within a
Docker container fails.

The reported error is:

seccomp-filter.c:168:11: error: static_assert expression is not an integral 
constant expression
  verify ((uintptr_t) NULL == 0);
  ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
../lib/verify.h:273:32: note: expanded from macro 'verify'
# define verify(R) _GL_VERIFY (R, "verify (" #R ")", -)
                   ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
../lib/verify.h:213:57: note: expanded from macro '_GL_VERIFY'
# define _GL_VERIFY(R, DIAGNOSTIC, ...) _Static_assert (R, DIAGNOSTIC)
                                                        ^
seccomp-filter.c:168:11: note: cast that performs the conversions of a 
reinterpret_cast is not allowed in a constant expression
1 error generated.
make[1]: *** [Makefile:433: seccomp-filter] Error 1
make[1]: *** Waiting for unfinished jobs....
make: *** [Makefile:419: lib-src] Error 2

Thank you,

In GNU Emacs 28.0.50 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.24.28, cairo 
version 1.17.4)
 of 2021-04-08 built on ab91f5cae90f
Repository revision: 1000227d38b4f139f1e393e6bfb613829fcc92d0
Repository branch: pgtk-nativecomp
Windowing system distributor 'System Description: Arch Linux

Configured using:
 'configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
 --localstatedir=/var --mandir=/usr/share/man --with-gameuser=:games
 --with-sound=alsa --with-modules --with-x-toolkit=gtk3 --with-cairo
 --with-xwidgets --with-native-compilation --with-pgtk
 --without-compress-install --without-gconf --without-gsettings
 --without-m17n-flt --enable-autodepend --enable-link-time-optimization
 CC=/usr/bin/clang 'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe -fno-plt -g
 -flto' LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now
 CPPFLAGS=-D_FORTIFY_SOURCE=2 'CPP=/usr/bin/clang -E''

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM HARFBUZZ JPEG JSON LCMS2 LIBOTF
LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY PDUMPER PGTK PNG RSVG
SOUND THREADS TIFF TOOLKIT_SCROLL_BARS XIM XWIDGETS GTK3 ZLIB

Important settings:
  value of $LC_COLLATE: C
  value of $LANG: en_GB.UTF-8
  locale-coding-system: utf-8

Major mode: N/A

Minor modes in effect:
  N/A

Load-path shadows:
None found.

Features:
(nativecomp emacs)

Memory information:
((conses 16 1568937 1176236)
 (symbols 48 70381 51)
 (strings 32 262321 70216)
 (string-bytes 1 8574627)
 (vectors 16 155314)
 (vector-slots 8 4893116 597798)
 (floats 8 1233 1802)
 (intervals 56 5595 1540)
 (buffers 992 17))

-- 
---
Méril Pilon